There are two traditional classifications of juvenile arthritis: the
European classification of juvenile chronic arthritis (JCA) and the American
classification of
juvenile rheumatoid arthritis (JRA). Because these
classifications break down into different categories, European and American
research findings and treatment recommendations are difficult to use
interchangeably.1
In an effort to improve research and treatment, the International
League Against Rheumatism has devised a unifying set of international criteria,
using the term "juvenile idiopathic arthritis." The word "idiopathic" means "of
unknown cause." First proposed in 1995 and later revised in 1997, this
classification is gaining favor among researchers and health professionals but
is not yet universally used.
The table below summarizes the three classification systems.1
Classification systems for juvenile
arthritis| Organization | Classification | Length of illness before diagnosis |
|---|
| American College of Rheumatology | Juvenile rheumatoid arthritis (JRA)
- Systemic JRA
- Polyarticular
JRA (5 or more joints)
- Pauciarticular JRA (1 to 4 joints)
JRA does not include similar types of childhood arthritis
(juvenile ankylosing spondylitis, juvenile psoriatic arthritis). | 6 weeks |
| European League Against Rheumatism | Juvenile chronic arthritis (JCA)
- Systemic JCA
- Polyarticular
JCA (5 or more joints, RF-negative)
- Juvenile rheumatoid arthritis
(5 or more joints, RF-positive)
- Pauciarticular JCA (1 to 4
joints)
- Juvenile psoriatic arthritis
- Juvenile ankylosing spondylitis
| 3 months |
| International League Against
Rheumatism | Juvenile idiopathic arthritis (JIA)
- Systemic
JIA
- Polyarticular JIA, RF-positive
- Polyarticular JIA, RF-negative
- Oligoarticular JIA
- Persistent (1 to 4 joints)
- Extended (eventually affecting 5 or more joints)
- Psoriatic arthritis
- Enthesis-related arthritis
- Other arthritis
| 6 weeks |
Regardless of the classification, children who develop symptoms
before reaching 16 years of age are considered to have juvenile arthritis.